LXR linux/arch/sh/mm/uncached.c

   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/init.h>
   3#include <linux/module.h>
   4#include <linux/sizes.h>
   5#include <asm/page.h>
   6#include <asm/addrspace.h>
   7
   8/*
   9 * This is the offset of the uncached section from its cached alias.
  10 *
  11 * Legacy platforms handle trivial transitions between cached and
  12 * uncached segments by making use of the 1:1 mapping relationship in
  13 * 512MB lowmem, others via a special uncached mapping.
  14 *
  15 * Default value only valid in 29 bit mode, in 32bit mode this will be
  16 * updated by the early PMB initialization code.
  17 */
  18unsigned long cached_to_uncached = SZ_512M;
  19unsigned long uncached_size = SZ_512M;
  20unsigned long uncached_start, uncached_end;
  21EXPORT_SYMBOL(uncached_start);
  22EXPORT_SYMBOL(uncached_end);
  23
  24int virt_addr_uncached(unsigned long kaddr)
  25{
  26        return (kaddr >= uncached_start) && (kaddr < uncached_end);
  27}
  28EXPORT_SYMBOL(virt_addr_uncached);
  29
  30void __init uncached_init(void)
  31{
  32#if defined(CONFIG_29BIT) || !defined(CONFIG_MMU)
  33        uncached_start = P2SEG;
  34#else
  35        uncached_start = memory_end;
  36#endif
  37        uncached_end = uncached_start + uncached_size;
  38}
  39
  40void __init uncached_resize(unsigned long size)
  41{
  42        uncached_size = size;
  43        uncached_end = uncached_start + uncached_size;
  44}
  45